1. Field of the Invention
The present invention relates to an automatic exposing apparatus for exposing two sides of a work, and a method of exposing thereof, in which a substrate is exposed with a fixed pattern on both sides through respective masks by irradiation with ultraviolet rays.
2. Prior Art
Recently, there have been offered various kinds of automatic exposing apparatus for exposing two sides of a work substrate with a predetermined pattern by irradiation with ultraviolet rays having a fixed wavelength. For example, there is an apparatus to which a substrate transfer mechanism is applied, in which the substrate is transferred by a handler that moves in coming and going directions, and that provides suction pads for holding the substrate. There is also another transfer mechanism in which the substrate is transferred by a driving roller or a driving belt, on which the substrate is mounted.
In such apparatus, the substrate is exposed on both sides after aligning each side thereof. Generally, this method comprises first exposing the substrate on one side, then reversing or turning over the substrate from its upper surface to its under surface by a reversing device provided in the substrate transfer route, and again, exposing the substrate on another side which is transferred by the substrate transfer mechanism.
In addition, there are various constructions of the light source mechanism. In each, the optics reference (such as a reflector, fly-eye-lens, or cooling mechanism and the like) must be arranged in the inside of the apparatus and it is necessary to secure the substrate transfer route and the substrate transfer mechanism.
Accordingly, as for the current automatic exposing apparatus for exposing a work on two sides, the constitution is extremely complicated.
However, as for the current automatic exposing apparatus said above, there is room for improvement, and to solve the problem as follows.
(1) The current automatic exposing apparatus for exposing on two sides of a work (or called xe2x80x9cautomatic both side exposing apparatusxe2x80x9d as follows) described above has a substrate transfer mechanism including a handler, a carrying-out roller, and the like devices. An increased number of such devices are provided in the route for delivering the substrate. In the case of each serial process, devices are provided for the substrate transfer, the aligning, the exposing and the like. It becomes necessary to secure both a delivery space and a delivery time. The need for adequate delivery space and time increases the opportunity for dust to stick to the substrate. It is desirable, therefore, to provide a constitution for holding the delivering movement of the substrate in check and to a minimum.
(2) As for the current automatic both side exposing apparatus described above, since the substrate transfer mechanism thereof is complicated, and moreover, a reverse constitution for allowing the substrate turn over is provided separately, the size of the whole assembly is enlarged and raises an inconvenience inasmuch as a sufficient area is needed for the assembly.
(3) There is a constitution of the automatic both sides exposing apparatus using the collimator reflecting light as parallel light indicated here by Japanese Patent Examined Publication No.1995-78630, and, according to the constitution, the collimator reflecting system is to be put and arranged between two substrates. However, due to said above constitution, in order to expose the substrate on both sides, it is required to provide the reversing device to reverse or turn over the substrate from its upper surface to its under surface. Also, it is required for the handler to deliver the substrate to another printing frame. Consequently, the reversing device and handler expand the size of the apparatus, as mentioned above.
In view of the forgoing problems, the present invention is suggested.
An object of the present invention is to provide an automatic exposing apparatus for exposing a work on two sides wherein a frequency that the substrate is delivered is minimized, where the substrate can be turned over without a reversing mechanism, where the substrate can be transferred (and delivered) at good efficiency in limited space and exposed accurately, where any inconvenient origin for the substrate is able to be minimized, and where the apparatus is made compact.
According to the present invention, there is an automatic exposing apparatus for exposing a work substrate having first and second sides provided, which comprises a first exposing mechanism having a first mask, a second exposing mechanism having a second mask, a carrying-in portion from which the work substrate is delivered to the first exposing mechanisms, a carrying-out portion for the substrate to which the work substrate is delivered from the second exposing mechanism, a first holder for closely fixing the work substrate and placing the first side of the work substrate in contact with the first mask so that the first side faces the first exposing mechanism, a first optical system, a second holder for closely fixing the work substrate and placing the second side of the work substrate in contact with the second mask, and a second optical system.
Further, the first holder and the second holder respectively have first and second holding means to hold the substrate, and a place for delivering the substrate is provided, to which each of the first exposing mechanism and the second mechanism is opposite respectively. The substrate is delivered to the second holder from the first holder, wherein the substrate is turned over from upper surface to under surface.
With the constitution mentioned above, as to the automatic both sides exposing apparatus according to the present invention, each of the first and the second holders thereof serve not only as a printing frame but also as the substrate reversing or turning over device.
Furthermore, the first holder of the automatic both sides exposing apparatus is movable, while holding the substrate, over a first driving course that is made from said carrying-in portion by the first exposing mechanism to said delivering place of the substrate.
The second holder is movable, while holding the substrate, over a second driving route that is formed from the delivering place of the substrate by the second exposing mechanism to said carrying-out portion.
With the construction made in this way, as to the automatic both sides exposing apparatus, there is the substrate provided, which is not only transferred from the carrying-in portion to the carrying-out portion by the first and the second holders, but also, turned over from upper surface to under surface by the same and exposed by the first and the second exposing mechanisms that collaborates with the first and the second holders, respectively.
Furthermore, as to said holding means for the substrate of the automatic both sides exposing apparatus, there is provided a negative adsorbing mechanism such as a vacuum suction mechanism or an adsorption mechanism based on Bernoulli theorem, in which the substrate is supported tight or held in the holder by the negative pressure.
The first exposing mechanism and the second exposing mechanism of the automatic both sides exposing apparatus each comprises a transparent plate holding said mask, an alignment mechanism, in which the transparent plate is moved so as to match a position of the mask to that of the substrate, a supporting frame mechanism holding the alignment mechanism, and a working mechanism, which can let the supporting frame move in the direction of the substrate.
In this way, in each of the first exposing mechanism and the second exposing mechanism, it is possible that the mask remain stuck to or near contact with the substrate by virtue of said working mechanism, and that a gap of a position between the substrate and the mask is confirmed and an alignment of the mask and the substrate is to be performed, and the substrate is able to be exposed in accordance with the mask.
Moreover, the automatic both sides exposing apparatus further comprises a holding side sliding mechanism, in which one of the first holder and the second holder at least slides or moves the substrate held by said holding means in the direction of the other holder.
With the constitution made in this way, slipping or positional deviation of the substrate is minimized, when it is slid or moved, and there are more transfer or driving routes of the substrate to be prepared.
Furthermore, at least one of the first holder and the second holder has a moving loci in the shape of rectangle, which is made of two straight long lines and two short straight lines. Also, the first and second holders are to meet each other in one of the short straight lines for delivering of the substrate. With this structure, since the first holder and the second holder can move and operate independently in each driving route respectively, shortening of the tact time is possible, and the efficiency can work well.
Moreover, each of the holders comprises a circulation moving mechanism for moving the holders. The circulation moving mechanism comprises a supporting arm holding one of the both holders respectively, a move control body having a supporting arm and a carrying rail for moving the first holder or the second holder through a respective one of the moving control bodies.
As constituted in this way, each of the holders moves fast along the rail, while the substrate remains in good position.
Besides, the optical system may comprise a collimator reflecting mirror arranged outside the position at which the substrate is exposed, provided that the position is determined as xe2x80x9cinsidexe2x80x9d.
With the construction built in this way, by joint work of both exposing mechanisms and both holders, it is possible to expose the substrate on two sides at higher efficiency.
Furthermore, according to another important object of the present invention, there is a method of exposing the substrate on two sides suggested, which comprises first for the substrate to be delivered to the first holder in the carrying in portion, for the first holder to be moved to an exposing treating position while holding the substrate and to be stopped there, for the first exposing mechanism to be advanced before the substrate and for the substrate to be stuck on a first mask held by a first transparent plate, for an alignment of the first mask and the first side of the substrate to be performed, due to confirming the positional difference between the first mask and the substrate through a camera, for the first side of the substrate to be exposed on through the first mask by parallel light from a first collimator reflecting mirror.
The method further comprises, subsequently, for the adsorption between the substrate and the mask to be released, for the substrate held by the first holder to be faced at the second holder moved from an (evacuation) position at which the second holder has taken refuge and for each of the sides of the substrate to be stuck on each of the holders respectively, wherein one holder moves at least in direction of each other, so that for the substrate to be delivered from the first holder to the second holder with the face and the back exchanged.
Furthermore, after the first holder has delivered the substrate, the first holder is permitted to be moved in the direction of the carrying-in portion, while the second exposing mechanism is slid to the substrate held by the second holder and a second mask held on a second transparent plate is stuck on the substrate. After confirming the positional difference between the mask and the substrate by camera, for the alignment to be performed, the second side that is aligned of the substrate is exposed by parallel light reflected on the second collimator reflecting mirror through the second mask of the second exposing mechanism. After the coherence with the substrate and second mask is removed, the substrate held by the second holder is moved in the carrying-out portion, where the substrate is taken out.
Owing to the mentioned above constitution, the frequency at which the substrate is delivered to the first and second holders is minimized, and the face and back of the substrate can be exposed.